Is primary storage deduplication going entirely mainstream?

Storage vendors are very passionate about the topic of storage deduplication. Vendors who offer storage deduplication, tout it, while vendors who don’t offer it, discredit it. Before I go too far, let’s agree on what we are talking about so we can disagree later: When I say primary storage, I’m referring to non-backup storage, so these are the logical unit numbers (LUNs) that are providing storage resource for file servers, databases, and virtual machines. When I say deduplication, I’m referring to a technology (blocks, pages, or files) that removes the storage consumption of like areas on disk.